This R21 project is designed to explore the potential for information storage in water clusters, or aggregates, which could constitute the molecular basis for homeopathic practice. The possibility that information could be stored in water aggregates has been implicit in past work, albeit controversial. Recently, it was demonstrated that water is impacted by various surfaces in a profound way: The water adjacent to the surface excludes large solutes, and the solute-exclusion zone is much larger than anticipated (Zheng and Pollack, 2003); hence considerable water is involved. More recent studies show that the solute-exclusion zone has a character different from that of ordinary water, and that it is stable for extended periods. Hence, the possibility exists that such water might carry long-term information about the molecular structure to which it had been exposed. The proposed studies will explore this possibility. They will pursue two specific aims: first, to determine whether such water aggregates can remain intact for the long term when the original nucleation surface is removed; and, second, to determine whether these aggregates contain information about the surface. If the hypothesis is supported and confirmed by more extensive studies, it may provide a vehicle for understanding why solutions with compounds that are extremely diluted can have biological effects not unlike those in high concentration.